Abstract
Attenuating the Taxol yield of Aspergillus terreus with the subculturing and storage were the technical challenges that prevent this fungus to be a novel platform for industrial Taxol production. Thus, the objective of this study was to unravel the metabolic machineries of A. terreus associated with attenuation of Taxol productivity, and their restoring potency upon cocultivation with the Podocarpus gracilior microbiome. The Taxol yield of A. terreus was drastically reduced with the fungal subculturing. At the 10th subculture, the yield of Taxol was reduced by four folds (78.2 µg/l) comparing to the original culture (268 µg/l), as authenticated from silencing of molecular expression of the Taxol-rate limiting enzymes (GGPPS, TDS, DBAT and BAPT) by qPCR analyses. The visual fading of A. terreus conidial pigmentation with the subculturing, revealing the biosynthetic correlation of melanin and Taxol. The level of intracellular acetyl-CoA influx was reduced sequentially with the fungal subculturing, rationalizing the decreasing on Taxol and melanin yields. Fascinatingly, the Taxol biosynthetic machinery and cellular acetyl-CoA of A. terreus have been completely restored upon addition of 3% surface sterilized leaves of P. gracilior, suggesting the implantation of plant microbiome on re-triggering the molecular machinery of Taxol biosynthesis, their transcriptional factors, and/or increasing the influx of Acetyl-CoA. The expression of the proteins of 74.4, 68.2, 37.1 kDa were exponentially suppressed with A. terreus subculturing, and strongly restored upon addition of P. gracilior leaves, ensuring their profoundly correlation with the molecular expression of Taxol biosynthetic genes. From the proteomic analysis, the restored proteins 74.4 kDa of A. terreus upon addition of P. gracilior leaves were annotated as ribosome biogenesis proteins YTM and microtubule-assembly proteins that belong to WD40 superfamily. Thus, further ongoing studies for molecular cloning and expression of these genes with strong promotors in A. terreus, have been initiated, to construct a novel platform of metabolically stable A. terreus for sustainable Taxol production. Attenuating the Taxol yield of A. terreus with the multiple-culturing and storage might be due to the reduction on main influx of acetyl-CoA, or downregulation of ribosome biogenesis proteins that belong to WD40 protein superfamily.